3.
1) I was studying last night
2) My parents were working last Saturday
3) It was rainig yesterday
4) We were doing an exam at 9 o'clock
5) I was waiting for you
6) We were speaking English
4.
1) I wasn't studying last night
2) My parents weren't working last Saturday
3) It wasn't rainig yesterday
4) We weren't doing an exam at 9 o'clock
5) I wasn't waiting for you
6) We weren't speaking English
5.
1) were you sleeping ...
2) was your mum working...
3)were you watching...
4)was your teacher talking ...
5)were you studying ...